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I’ve had to change my heater valve twice now, and it ends up being a real pain in the butt. It’s the one offered by the major parts houses; it threads into the intake manifold at the rear. The shape of this valve requires that I detach the transmission dipstick tube in order for there to be enough room to unscrew the valve out and install the new one, and my fat old guy hands are just baaaaaaaarely able to get in there and thread that bolt out to get the dipstick tube detached.
My solution is to install a 5/8” hose barb in the intake manifold, hook the hose directly to that, and splice an inline-style heater valve in the hose a few inches downstream of the barb.
I figure I can’t be the only one to have thought to do this, so I’m wondering if anyone has found a good vacuum-controlled inline heater valve they’d recommend. A lot of similar GM makes from that era seem to have heater valves like my original one, which would still be a pain to screw/unscrew, so maybe I'm looking at a Mopar one or even one from *shudder* FoMoCo.
Any suggestions before I go start wandering the part stores? Thanks!
Before wandering too far from OEM, realize that Olds changed the actuation on the Cutlass heater control valve around 1970. Make sure you know if you want vacuum-to-open or vacuum-to-close when you get a brand X valve.
Someone will comment on which you need. I don't have that in my memory bank.
My response is certainly not to confuse you, but this topic raises its head quite often. Here is a thread which might provide a tad bit of insight until one of the heater valve gurus respond.
NOTE: The discussion about the 1972 model year by other members (might be beneficial to you). Good Luck!
Yes there are “other makes” heater valves that are inline with the heater hose and not screwed into the intake. As VC455 said above, you need to ensure you get the correct vacuum operation; other than that your Olds won’t know that it’s a Ford, Chevy, or MOPAR valve.
I appreciate the feedback and the link - I’m pretty sure I found one that will work. I’ll update when I confirm. Might even post pics for anyone else wanting to go this.
1972-older Cutlii use a valve that is normally closed and opens when vacuum is applied. Most valves available today work opposite of that. The easy way to tell is to try to blow through the valve when it is not installed. If you can, it's the wrong one.
Spent $20 at O’Reilly’s for the exact heater valve I had in mind. Part number at O’Reilly’s Not as big as I thought it would be. Here it is installed, and you can see the 5/8” hose barb and brass bushing threaded into the intake manifold. MUCH easier to deal with than threading in the old brass unit. I had to get the adapter on Scamazon; it’s a 1/2” NPS female to 3/4” NPT male reducing bushing. I chose 1/2” on the female side because it’s super common for whatever you want to screw into it.
Go back and read post #7. 74612 is a normally open valve that closes when vacuum is applied. That is the opposite of what your car needs. Your next thread will be asking why you have heat all the time or not when you want it. By the way, I used that valve on my 1985 307 cars for exactly the same reason. It works great there because those cars need the normally open valve.
The one you needed based on what?
Humor me. With the engine running and the heater control in the HEAT position, do you have vacuum on the hose to the valve or not? How about when the heater control is in the MAX A/C position?
Originally Posted by joe_padavano;[url=tel:1678614
1678614[/url]]The one you needed based on what?
Humor me. With the engine running and the heater control in the HEAT position, do you have vacuum on the hose to the valve or not? How about when the heater control is in the MAX A/C position?
With the heater on, but turned all the way to “cold”, I have vacuum to the heater valve, so it’s closed. As soon as I turn it at all towards “warm”, the vacuum drops out, the valve opens. Anything else?
To keep the OEM valves alive and the rest of the cooling system make sure coolant isnt acidic. Actuate the valve every time you're in the car...or at least when you think about it.
